|
Endo-polygalacturonase was purified from tomato, Lycopersicon esculentum L. The purification procedures included gel filtration on Sephadex G-150 and DEAE-cellulose ion exchange chromatography. Yield of the enzyme purification was 12.74 %. Purified enzyme was confirmed as a active single band by the SDS-polyacrylamide gel electrophoresis. When the purified enzyme was applied to SDS-PAGE, the molecular weight was estimated about 50,000. The optimum pH for the enzyme activity was 5.0 and the range of its stability to the pH was 4.0 to 5.0. The optimum temperature was 50℃, while the enzyme was abruptly inactivated above 50 ℃. From the result of the study on the effects of metals ion, it was found that Ag^+, Zn^(++) and Mg^(++) increased on the enzyme activity. In contrast, Ba^(++), Hg^(++), Pb^(++), Ca^(++), Mn^(++), Cu^(++), Fe^(++), Na^+ and K^+ decreased it. the reaction catalyzed by this enzyme followed typical Michaelis-Menten kinetics with the Km value of 1.43 × 10^(-1) ㏖/l.
|